Inductive rotational sensors are described in our co-pending patent application Ser. Nos. 11/399,150, 11/102,046, and 11/400,154, the contents of all of which are incorporated herein by reference.
However, rotational sensors inherently restrict the distance of travel that can be measured in certain applications, for example, electronic throttle controls for automobiles. The use of linear sensors, or sensors sensitive to motion including a linear component, may provide more sensitive measurements over a longer travel range.
Signals from the receiver coils of inductive sensors are prone to variation due to noise and manufacturing variations, for example variations in part separations. Improved sensors giving positional signals corrected for such common mode factors would be of great commercial interest, particularly for electronic throttle control applications, amongst many other possible applications.